Samuel h



(No Model.) 2 Sheets-Sheet 1.

' SQH. BARTLETT & E. WAITE.

TRANSMITTER FOR TELEPHONES.

No. 253,665. Patented Peb.14,1-882.-

(No Model.)

N. PEI'ERS. Fholmlflhagmphcr. Washingmn. D. c.

2 Sheets-Sheet 2.

S. H. BARTLETT & H. E. WAITE.

TRANSMITTER FOR TELEPHONES.

Patented Feb. 14,1882.

, Ev e-722 026,

UNITED STATES PATENT OFFICE.

SAMUEL H. BARTLETT AND HENRY E. WAITE, OF NEW YORK, N. Y., ASSIGNORS TOCHAS. F. LIVERMOBE, OF SAME PLACE.

TRANSMITTER FOR TELEPHONESQ SPECIFICATION forming part of Letters PatentNo. 253,665, dated February 14, 1882.

Application filed January 9, 1882. (No model.)

To all whom it may concern Beit known that we, SAMUEL H. BARTLETT andHENRY E. WAITE, of New York, county of New York, and State of New York,have invented new and useful Improvements in Transmitters forTelephones, of which the following is a full, clear, and exactdescription, reference being had to the accompanying drawings, makingpart of this specification, in which- Figure 1 is a perspective view ofour improved transmitter with the hinged cover raised. Fig. 2 is a planor top view of the apparatus with the cap-plate removed. Figs. 3 and 4are vertical sections through the apparatus ortransmitter. Fig.5 is aplan view similar to Fig. 2, showing a number of tripods; and Fig. 6 isaperspective view of one of the tripods.

Our invention relates to an improvement upon whatisknown as the Reisstransmitter, our transmitter being similar in form and in thearrangement of its parts, and varying mainly in the materials employed.In the apparatus of Reiss a flexible membrane or diaphragm was employed,susceptible of mechanical vibration under the action of the soundwaves,and dependent upon such vibration in the production of the desiredresult, whereas we employ a floor or plate of cork, wood, felt, or othersuitable material capable of conveying the disturbance produced by theaction of the sound-waves impinging upon its surface to the microphoneby molecular action rather than by mechanical movement of the flooritself, said floor being loosely supported or upheld in itssupporting-standin such manner as to leave it untrammeled, and beingprovided with a button or plate of carbon or equivalent material, withwhich the point on the tripod at its angle rests in contact, the pointsat the ends of the arms of said tripod resting also in cups or blocks ofcarbon or its equivalent, in lieu of the piece of platinum and the cupof mercury employed by Reiss.

Our invention further relates to certain details of construction forgiving increased efficienoy to the transmitter through multiple contact,850., as hereinafter explained.

In the accompanying drawings, A represents a box or case; B, its hingedtop or cover, and

O the mouthpiece, said parts being similar in construction andarrangement to the corresponding parts of the Boise transmitter referredto, except that, if preferred, the box may be maderound, polygonal, orin any other suitable form, instead of square, as shown. The cover B hasa circular opening, D, cut in it, provided with annular shoulders orrabbets d d in its side walls, upon the lower one, d, of which a flooror block, E, of cork, wood, felt, or other suitable material issupported, said floor being of slightly less diameter than the openingabove the rabbet d in which it rests, so as to leave it unbound at itsedge or periphery and untrammeled in any direction except sufficientlyto be upheld lightly. The floor is provided with one or more smallbuttons or disks, E, of carbon or its equivalent, forming one of theelectrodes, connected by wire a with one of the binding-posts F F,through which connection is made with the line or circuit in any usualmanner.

Upon the floor E is placed a tripod, bar, or plate, G, of metal, made inangular or hellcrank form and provided at the angle with a pendent spuror point, 9, of platinum, carbon, or equivalent material, which restsupon the button E. both be provided at their ends with similar points orspurs, g, which rest in cups or recessed blocks h, of carbon or itsequivalent, let into or penetrating the ledge or annular rabbet d, andconnected by wire 0 or other suitable conductor with the binding-post F,and thence with the line or circuit. In the drawings only one of thearms is shown provided with the platinum or carbon point resting in acarbon cup, the other being shown perforated and held in place by meansof a pin or spur on the ledge or rabbet d. Either construction may beused, but the first named is preferred, as with pendent spurs on botharms resting in cups or recessed blocks of carbon, not only are theplates retained in proper position, but an additional point of contactis secured.

The apparatus above described, it will be seen, is similar in thearrangement of its parts to thatofReiss referred to, with thedifferenceviz., that the drum-head or diaphragm of membrane employed byReiss is removed, and a The arms of this angular bar may solidnon-vibrating floor of cork or other suitable material provided with acontact-button or electrode of carbon or other suitable material issubstituted therefor, and permanent c011- tact-cups of carbon or itsequivalent are substituted for the cup of quicksilver employed bybutton, E, and at the ends of the arms with similar spurs resting in thecarbon cups, the latter being connected with each other and with thebinding-post F by suitable conduct-- ors, as shown, in such manner thatif for any reason any one or more of the tripods should becomeinoperative the transmitter will still continue to operate through theothers; or, if desired, the several tripods may serve to connect eachwith an independent line or circuit for conveying the message todifferent points.

The floor E rests upon the ledge 61 by its own gravity and the tripodsor angular plates or bars G rest in a similar manner on said floor andthe cups of carbon described, and the latter are covered in practice bya cap-plate, or cover, H, of cork or other suitable material, removedfrom actual contact with the upper faces of the tripods, but arranged insufficiently close proximity thereto to prevent their displacement inhandlingor overturning ofthe apparatus without interfering with theirfreedom of movement when in use.

By the construction and arrangement shown an exceedingly efficienttransmitter is secured, one which is simple and cheap in manufacture andwhich is not liable to get out of order. Its operation will be readilyunderstood without further description.

Having now described our invention, we claim- 1. In atelephone-transmitter, a floor of cork or equivalent material providedwith a contact-button or electrode of carbon and loosely resting in asupporting-stand, in combination with recessed blocks of carbon orequivalent material secured to the supporting-stand, and a metallictripod provided with pendent points resting on said button and recessedblocks, substantially as described.

2. The combination, in a telephone-transmitter, of a floor looselyupheld in its stand or support and provided with a contact-button orelectrode, recessed blocks or cups of carbon or its equivalent, and aseries of tripods provided with pendentpoints or spurs and resting bygravity on said recessed blocks or cups and button, substantially asdescribed.

In testimony whereof we have hereunto set our hands this 7th day ofJanuary, 1882.

SAMUEL H. BARTLETT. HENRY E. WAITE. Witnesses:

(J. H. HANKINSON, F. O. BARTLETT.

